Apparatus for liquefying air and other gases.



110. 830,013. PA1PN1PD SPP1. 11, 1000.

P.. 11.110111. APPARATUS P011 1.1001111110 A111 A1111 01111111 GASES.

APPLICATION FILED JAN. 12, 1901.

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UNITED ,STATE'SPATENT OFFICE y y l nacer. PIERRE rrcra'r, 0E NEW YORK,N. Y. YAEP/ausm*lis Fon LIQUEFYINQ A lnf AND ori-Isn casses.`

. Na. asocia.v

Tala/ZZ whom tilt may concern 1 `My invention relates to lmprovementslin` apparatus for-liqu'efying air or other gases capableof' being iueiied only vat loW temperatures and usual y under pressure.

My invention consists 1n the novel construction, character, andarrangement of the cooling devices employed for cooling the 'enteringcurrent of air or other gas, in the novel means em loyed for reducingrthe pressure of the lique ed gas without the evolutionI of heat .in theapparatus due to such reductlon in pressure and with minimum evaporation'of the liquid, in the employment of means for converting into usefulwork the energy Vcontained within the liquefiedgas prior to itsreduction in novel combination, construction,- and arrangement of theparts ofthe apparatus. J

The objects of my invention are, first,- to liquefy air and othergasesmore efficiently and with less expense than has been possible heretoforesecond, to prevent so far as possible evaporation of the liquefied gasas an incident to the operation'of the apparatus;

third, to prevent so far as possible the productionA of heat in the vaparatus; fourth, to convert into useful wor so far as Apossible theenergy existingin the liquefied gas after liquefacti'on and prior to thereduction of the pressure -on the liquid, and generally to make theapparatus as simple, economical, efi'- cient, and easily operated aspossible. These objects are attained" in the apparatus herein described,and illustrated in the drawing which accompanies and forms a part ofthis application, in which the main portion ofthe apparatus-viz., theliqueiier-is shown in section, the other portions of the ap aratus beipgindicated diagrammatically an not to sca e. T he general method ofoperation ofthe apparatus herein illustrated and described is asfollows: Air or other gas to be liquefied which has irst been dried andfiltered, if necessary, is compressed. In 'the case of air thespeeificnon of wcm Patent.

- I f j Ammonia aaa :muy 12,1901. seau n. 42.951.-

and exact descrip- `evaporation, and

ressure, and generally in theI degree of compression need not be greaterPatented sept. 11, 190e.

than fifty-three atmospheres, this pressure I corresponding to thecritical temperature of liquefaction of air. The air or rother gas socompressed is passed through a succession-of coohng coils, p1pes,.orpassa es, themselves cooled b'y contact with a'rapi ly-evaporatin liquidrefri erating a ent, such as li uid Asu furous acl l1 ueie ammonia, chorid of ethyl, o r any ot er volatile liquid used inrefrigeratlng-machines.

use the mlxture of sulfurous andcarbonio I prefer, however7 to lacidsknown as liquide Pictet. A combined vacuum andcompression ump creates avacuum above the body o evaporatlng' rerigerating agent, so as to hastenthe at the, same time compressesY the gas so drawn off and passes itthrough a condenser, so as to liquey itA again. ^From these coolin-coils the compressed and cooled air or ot er enterin gas, which by thetreatment 'just mentione may have been cooled to or 100centigrade,

-is Vpassed through other cooling coils', pipes, or

passages themselves subject to the action of a liquid refrigeratingagent having a much lower boiling-point than that liquid which cools theprimary cooling-coils and which is itself evaporated, compressed,condensed,

and returned in the same manner as the pri-l ma refrigerating agent. Bythis second coollng the entering current of air or .other gas to beliquefied may usually' be cooled to `such a temperature that under thepressure to which it has been compressed it will liquefy. For thesecondary refrigerating agent I preferably employ ethylene or protoxidof nitrogen, either of whieh'agents permits the cooling of air to from140 to 150o centigrade. The air thus liquefied lis under considerablepressure, and to permit it tovbe stored economically or to be used formost purposes it must be relieved of this pressure. This ma beaccomplished most expeditiously by a lowing the liquefied air to escapethrough a suitable orifice and fall into a suitable receptacle;butbecause of the pressure to which it is subjected the liquid air insoissuing will have great velocity,` and if the jet be interrupte ordefiected downward by av suitable baHie-lplate the energly of therapidly-moving partie es of liquid Wil be converted into heat,

which is objectionable for two reasons-rst,

will be caused to evaporate, and, second, be-

IIO

cause the ener wasted. For t 's reason I preferably locate in front ofthe jet a turbine'or other suitable fluid-motor operated by the impactuponit designates the outer casin of the lliquefier,

so converted into heat isv absorbe Without the evo ution o anyconsiderable amount of heat within the apparatus in so doing, and theener so imparted to the fluid-motor may be a sorbed in operatingmachinery of any t e, and therefore ma if desired, be returne to thesystem.

referring now to the drawing, numeral 1 which casing is a cylindricashell. Within it is la second casing2, connected tocasing 1` at .to andbottom and inclosing, with casing 1, a'jacket3, adapted to contain avolatile fluid and Aalso contaming pi e-coil 4 and 5. The central spacesurroun ed by casing 2 is open atto and bottom. In this s ace is asecond vessell formed by casings 6 an 7, together inclosing a jacketadapted to contain a volatile fluid and containing a pipe-coil'8. Thesecond or inner jacket is numbered 9. This sec'- .ond vessel is open atthe bottom, but is closed at the top by a cover-plate 10. Within thesaid vessel is still a third vessel 11, and within vessel 11 is a tube12, open at the bottom. Within the space between the walls of vessel =11and tube 12 is a helical partition 13, divid'- l Zing this chamber so asto make it a helical assa e, and within said helical passage are elicaipe-coils 14. Thevessel 11 has a conical ottom 15, to which apipe 16 forcar- 7 rying off the liquid air is connected.

. acid, 'liquefie vapors Numerals 17, 18, and 19 designatcthreecompressors. Compressor 17 draws atmosheric air or other gas from'afilter and deydrator 20, com resses said air to a pressure of from fiftyto l ty-three atmospheres, and -delivers the compressed air to the'coils' 4 within the outer jacket 3. This jacket contains the 'li uidePictet, liquid sulfurous d ammonia or chlorid of ethyl or other rimarrefrigerating agent which may have geen selected. Such liquid evaporatesrapidly in the jacket 3, the more sobecause .the com ressor 1 9 isarranged to draw off the fli'om the jacket 3 through a pipe 21 and-in sodoing maintains a considerable vacuum in the jacket. The vapors of the`primar refrigerant so drawn ofi"` are compresse by compressor 19 to .anextentsufii-v cient to liquefy them when cooled, and they are thenpassed through pipe 22, condenser- 23, wherein they are condensed andcooled, and pipe 24, 'back to thev jacket.

.of cold air until t .The prima? within the jac et 3 cools the enteringair in pipe-coils 4 and also the substance in the coils 5, whichis thesecondary refrigerant, such as protoxid of nitrogen or ethylene. Themain ody of this secondary refrigerant is contained inthe second jacket9, and the vapors which are formed in said jack'et 9 by the evaporationof the secondary reri erant are drawn off by the compressor 18 t ipe 25,are compressed .to a pressure of from ve to fifteen atmos heres, arecooled by passing through the coils 5', themselves cooled y the primaryrefrigerant, and are thereby liquefied, and are then returned throughpipe 26 to the jacket 9.

The gas to 'be liquefied after passing through the pipe-coils'4 immersedin the primary refrigerant is led by a pipe 27 to the pipecoils 8,immersed in the body ofthe secondary refrigerant contained'n the secondjacket 9. In its passage through these coils 8 the air or-other gas tobe liquefied is cooled rough the [refrigerant in evaporating to such anextent that being under considerable pressure it isliqueed, but althoughit is now a lllnd its pressure must be reduced to that of t e atmoshere, and likewise its temperature must be lowered to that of li uid air(or whatever other gas is being treate at atmospheric pressure. Toaccomplish this, the hquid alr or other substance is conducted b a pipe28 to the pi e-coils 14 within the he ical passages of t e vessel 11 andpasses downward through surrounded by an u wardly-moving current eliquid finally passes through a nozzle 29 and lmpinges upon the bucketsof a turbine-wheel 30, mounted upon a revoluble shaft 31, mounted withinthe tube 12. The liquid as it issues from the nozzle 29 has a highvelocity, due to the pressure which impels it; but upon encountering theturbine 30 the velocity of the liquid is irnlparted to the blades oftheturbine, the liquid itself falling downward. A portion of the liquidwill evaporate and will pass off through the helical channels of'thevessel 11, abstracting heat as it does so from the incoming air in thecoils 14 and so cooling such incoming air,"

but the proportion of liquid which thus evaporates is Very much lessthan would other- -wise be the case, owing to the use of the turbine 30,for if the energy of the stream of liq- IIO uid under pressure were notimparted to the v turbine it would be converted into heat through theimpinging of the liquid upon the sides of the apparatus or otherwise,and thus aiconsiderable proportion of the liquid would be evaporated.The energy imparted to the turbine is a measure of the energy thatotherwise would be converted intov heat in that part of the apparatusWhere it is least desirable that heat should be produced.

' The shaft 31 may be caused to drive suitable machinery, and therebythe power imparted to the turbine may be utilized and, jif

, desired, may be returned to the s stem in this manner. In the drawinthe ls aft 31 is shown as driving an electric ynamo 32; but of coursemachinery of any other type may also b'e driven therefrom. The shaft 31may also drive a meter 33 by which the amount ofliquid air produced maybe measured, 'for after the ap aratus is operating in the normal mannertlie `number of revolutions of the sha t31 in a given time will be ameasure of the amount of liquid air produced in that time.`

SuchI of the liquid air as evaporates'iand' passes upward throughthehelical passages ofthe vessel 11 passes downward through the annularspace between casing 7 and vessel 1 1 andthen upward through the annularspace between casings 2 and6. Such air therefore serves to chill to aconsiderable extent the entering air. evaporate asses out through thepipe A16 and may be col ected as produced.

'lheoperation of the apparatus is as follows: The three compressors 17,18, and *19 being driven from any suitable source comem lo ed as therimar refrigerant.

P y P presser 17 draws in air to be liquefiedfcompresses it to asuitable ipressure, which I prefer to be from fifty to fi ty-three atmosheres, and delivers it to the` co1ls` 4,iminersed) in the body ofprimary refrigerant within the jacket 3.- The compressor. 19 draws thevapors of the primary refrigerant from the jacket 3, in so doingproducing a partial vacuum in said jacket, and thereby hastening'the evaoration ofthe primary refri erant and maklng it possible to maintain are atively lowtemperature' in Ithe jacket 3. The compressor 19compresses such vapors to the `necessary extent to insure liquefaction,of such vapors upon cooling, and such vapors then pass through thecooler 23, are liquefied therein, and are then returned to the jacket 3.The entering compressed air in passing through the coils 4 is cooled toa tem creature of'from to 100 centigradei liquide Picl'eti air so cooledand still un er substantially the initial pressure next passes'throu hthe coilsl `8, nnmersed 1n the secondary re igerant 1n the jacket 9.Compressor 18'draws the vapors of this 'secondary refrigerant from the'jacket 9, in so doing producing a partial 'vacuum in said jacket, andthereby hastening the .evaporation of the secondary refrigerant andmaking it possible .to lnaintaina relatively low temperature in thejacket 9.4 The compressor 18 compresses such va ors to the necessaryextent to insure lique action of such vapors upon eoolingin thepipe-coils 5, immersed in the primary refri erant within the jacket 3,and suchA vapors t en pass through Athe coils 5, are condensed andcooled therein,

and are then returned` in the liquid state to thejacket 9. A `pressureof from six toeight The liquid air which does not,

will suflice to cause liquefa'ction of protoxid l5 of nitrogen orethylene, the secondary refrig-r erants preferably emplo ed in the coils5. Cooling of the entering air in the coils 8 sufi ces to reduce itstemperature to from 140 to 145 centigrade. The'air so cooled is thenpassed through the pipe-coils 14 in the helical passages of the vessel1 1. Cooling of the air to 140 to -1 145 centigrade in the coilsS undera pressure of from fifty to fifty-three atmospheres will suffice to liuefy air; but the air so'liquelied is neverthgless cooled to a stilllower temperature in its passage through the pi e-coils 14 by radiatlonof heat to the ,co der outgoing'current of air passing out- 'Ward aroundthe pi es 14. Fin ly the air so compressed, coole and liqueiied emergesfrom the nozzle or nozzles 29 as a stream ofV liquid air having a highvelocity, owing to the pressure behinditf, The energy of such jet orjets is imparted to the turbine 30 and so to theshaft 31 and themachinery driven there-` by, the liquid falling from the buckets of theturbine. A portion of this liquid will vaporize, because the temperatureof the liquid air issuing from thenozzles is not yet that of liquid'airat atmospheric pressure; 'but the evaporation of Ithisportion of the liuid air will cool the remainder of the liqui tothe temperature of lliuid airi at 'atmospheric pressure, and such' iquid will be collected bythey conical bottom 15 andV will descend through the pipe 16 and may becaught.

The jacket 3 serves both as an initlal cooler for the compressor 17 andas a condenser for' the secondary refrigerant. It is thereforeunnecessary to employ a separate initial cooler for the'compressor 17and a separate condenser for the secondary refri erant.

The air which passes up throug the helical passages of the vessel 11asses downward through the annular space etween vessel 11 and casing 7and then upward through the annular space between casings 2 and 6. In

so passing it helps to cool the primary and.

secondary refrigerante and also to insulate the passages 6V and 14against absorption of heat from the outside.

I do not limit myself to conducting the refrigeration of the enteringair in any particular number of stages or to the use of any particularrefrigerante. Nor doI limit myself to other gas capable ofbeingliquefied by the application of cold or of cold and pressure in t e sameway. p

I do not limit myself to the use of the particular 'construction andlarrangement of parts herein illustrated. j

Preferably two or more nozzles 27 should be employed, and these nozzlesshould be so s aced around the periphery of the turbine that side thrustis avoided.v In the drawing IOO IIO

the treatment ofairfor liquefying it by the method herein describedl Imay treat any' two such nozzles are shown, one being indiv cated bydotted lines.

The jackets or vessels 3 and 9 may be v refrigerants of successivelylower boilingpoints, each provided with cooling-passages, for conveyingthe gas to be liquefied through said cooling vessels, such passages ofthe said vessels being connected in series, and the ves sel forcontaining, the refrigerant of higher Vboiling-point having othercooling-passages connected with the vessel for containing refrigerant oflower boiling-point, and forming cooling-passages for the refrigerant oflower boiling-point, of means for compressing the vapor of therefrigerant of lower boilingpoint, and for passing it through thecorresponding,cooling-passages of the vessel containing the refrigerantof higher boilingpoint, back to its corresponding vessel, and means forcompressing the vapor of the refrigerant of higher ,boiling-point,cooling it and returning it to its corresponding vessel.

2. In an apparatus for liquefying air and other gases, the combination,with primary and secondary cooling vessels, adapted to contain,respectively, primary and secondary liquid refrigerants of progressivelylowei` boiling-points, said cooling vessels each provided withcooling-passages for the gasto be liquefied, said passages of the saidvessels being connected in series, the primary cooling vessel being alsoprovided with other coolingvpassages connected with the secondary vesseland forming cooling-passages for the secondary refri erant, of means forcompressing the* vapor o the secondary refrigerant, and for passing itthrough the cooling-passages of the primary vessel back to the secondaryvessel, and means for compressing the vapor of the primary refrigerant,cooling it, and returning it to the primary vessel.

3.. In an apparatus for liquefying air and other gases the combinationwith a series of cooling. vessels adapted to contain liquid refrigerantsof successively lower boilingpoints, located one within the other, andeach provided with cooling-passages, for conveying the gas to beliquefied through said cooling vessels, such passages of the saidvessels being connected in series, and the vessel for containing therefrigerant of higher boiling-point having other cooling-passagesconnected with the vessel for containing refrigerant of lowerboilingpoint, and forming cooling-passages `for the refrigerant of lowerboilingoint, of means Vfor compressing the vapor o the refrigerant iof,lowerw boiling-l point, and for passing it, throu'gh the correspondingcooling-passages of the vessel con-l taining the refrigerant of higherboilin -point back to its corresponding vessel, andi-means forcompressing the vapor of the refrigerant of higher boiling-point,cooling it, and returning it to its corresponding vessel.

4. In an apparatus for liquefying air and` other gases, the combination,with primary and secondary cooling vessels, 'located one within theother, and adapted to contain, re-

spectively,'primary and secondary li uid refrigerants of lprogressivellowerA oilingpoi-nts, said cool/ing vesses each provided withcooling-passages for the gas to be liquefied, said passages of the saidvessels being connected in series, the primary cooling vessel being alsoprovided with other coolingpassages connected with the secondary vesseland forming cooling-passages for the secondary refrigerant, of means forcompressing the vapor of the secondary refrigerant and forv passing itthrough the cooling-passages of the `primary vessel back to thesecondary vessel,

gas to be liquefied throug said coolin vessels, such passages of thesaid vessels eing proi vided with cooling-passa es, for conveyingconnected in series, and the vessel for containy ing the refrigerant ofhigher boiling-point having other cooling-passages for the refrigerantof lower boilingoint, of means for inducing circulation in t e severalcooling-passages, means for condensing and returning to ,1., the vesselfor containing the refrigerant of higher boiling-point, the refrigerantwhich evaporates therein, and a heat-exchan er., i

within the innermost of said vessels, provi ed wi th adjacent passagesfor enteringland outi going gas, and with an expansion-orifice c onfnecting the same.

6. In an ap aratus `for liquefying air `and f other gases, t ecombination with primary ifsv and secondary cooling vessels, the latterlo cated within the former, said vessels containing respectively primaryand secondary ref frigerants, the latter of lower boiling-point'.

than the former, said vessels provided with cooling-passages, connectedin series, for thez gas to be liquefied, the .primary vessel being alsoprovided with other cooling-passages connected with the secondary vesseland forming cooling-passages for the secondary refrigerant, of means forcompressing the vapor of the secondary refrigerant and for passing itthrough the corresponding passages of the primary vessel back to thesecondary vessel, and means for compressing the vapor of.

the .primary refrigerant, cooling it, and returmng it to the primaryvessel.

. passages connected with the secondary vessel and formingcooling-passages for the secondary refrigerant, of means for compressithe vapor of the secondary refrigerant, an for passing it through thecorresponding passages of the primary vessel back to the secondaryvessel, and means for compressin the vapor of the secondary refrigerant,co in it and returning it to the primary vessel, t e'heatexchanger beingarranged to cause unlique- {ied gas to pass back through the spacesbetween the exchanger' and the primary and secondary vessels.

8. In an apparatus for liquefying air and other gases, the combination,with primary and secondary cooling vessels, located one gg-frigerants ofprogressivel within the other, and adapted to contain, respectively,primary and secondary liquid relower boilingpoints, said cooling vesse seach rovided with cooling-passages for the as to e liqueiiod, saidpassages of the sai vessels being connected in series, the primarycooling vessel being also provided with other coolingpassages connected.with the secondary vessel and forming cooling-passages for the secondaryrefrigerant, of means for inducing circulation through the severalcooling-passages, means for condensing and returning tothe primaryvessel the refrigerant which eva orates therein, and a heat-exchangerwitin the innermost of said vessels, provided lwith adjacent passagesfor entering and outgoing yeying gas to be liqueiie gas, and with anexpansion-orlce connecting the same.

9. In an a paratus for liquefyin'g air and other gases, tlhe combinationwith a seriesof cooling vessels adapted to contain liquid refrigerantsof successively lower boiling-points, each provided with cooling-gaseses, for cont t roug said coolm vessels, such assa` es of the saidvessels being connected 1n series, and the vessel for' containing therefrigerant of higher boilingpoint havmg other cooling-passages for therefrigerant of lower boilingoint, of means for inducing circulation in t1e several cooling-passages, means for condensing and returning to thevessel for containing the refrigerantof higherboilin -peint,the-refrigerant which evaporates t erein, and a heat- Vexchanger withinthe innermost of said vessels, provided with adjacent passages forentering and outgoing gas, and with an expansion-orifice connecting thesame, there being a passage betweenrthe exchanger aud the adjacentcooling vessel, in communication with the outgoing passage of saidexchanger, f

through which the outgoin gas may flow.

10. In an a paratus for iiquefying air and othergases, tiie combination,with primary and secondary cooling vessels, located one withinthe other,and adapted to contain, respectively, lprimary and secondary liquidrefrigerants of progressivel lower boilingpolnts, said cooling vesse seach rovided with cooling-passages for the as to cliquefied, saidpassages of the sai vessels being connected in series, the primarycooling vessel being provided also with other coolingpassages connectedwith the secondary vessel and forming cooling-passages for the secondaryrefrigerant, ciJ means for inducing circulation through the severalcooling-passages, means for condensing and returning to the primaryvessel the refrigerant which eva crates therein, and a hcat-exchan erWit in the innermost of said vessels, provi( ed with adjacent passagesfor entering end outgoing gas, and with an ex ansion-orifice connectmgthe same, there )eing a assage be'- tween the exchanger and .theadjacent cooling vessel, in'communication with the outgoing passage ofsaid exchanger, through Whlch the outgomg gas may flow.

11. In an apparatus for liquefying air and other gases the combinationwit a series of coolin vessels, located one within the other,

and a apted to contain liquidrefrigerante ofv successively lowerboiling-points, each vessel Y rovided with.coolingpassages, for conveymggas to be 'liquefied through said cooling vessels, such tpassages of thesaid vessels being connecte in series, and the vessel for containing therefrigerant of higher boilingpoint havmg other cooling-passages for theIIO refrigerant of'lower boilingoint, of means for compressing the vaporo the refrigerant of lower boiling-point, andv for passmg it, throughthe corresponding cooling-passages of the vessel containin therefrigerant of higher boiling-point, bac to its corresponding vessel,means for com ressing the va or of the .refrigerant of big erboiling-point, cooling it and returning it to its corresponding vessel,and a heat-exchanger Within the last of said vessels, provided withadjacent passages for entering and outgoing gas, and

ywith an expansion-orifice connectmg the same, and a motor within theheat-exchanger arranged to be actuated by fluid issuing from saidorifice.

12. In an apparatus for liquef ing air' and other gases the combinationwit a series of coolin vessels, located one Within the other', and aapted to contain liquid reiriger'ants of successively lowerboiling-points,- each vessel provided with coolin pas\s\ages, forconveygas tobe liqueiie fromsaid coolin ves'` ses, such passages of thesaid vessels eing connected in series, and the vessel for containing therefrigerant of higher boiling-point i having other cooling-passagesfor-,the refrig` Id: lerant of lower lboiling-point, of means forcompressing the vapor of the refrigerant of lower boilingoint, andforpassing it, through thecorrespon ing cooling-passages of the Vesselcontaining .the refrigerant 'of higher boil- 1 5 ,ing-point; hack to itscorresponding vessel,

j rneans lforicompressing the yapor of the ref -f fri erantof lhigherr`helling-point, cooling it, an returning it-to its correspondin vessel,a heat-exchan erwithin thelastof said-Vessels, provided Wit adjacentpassagesfor entering and outgoing gas, 'and'with an expansion-oriiceco'nnectin the same, land a turbine-mo, tor within the eat-exchangerarranged to be actuated by fluid issuing from said orifice. Intestir'nony whereof-I affix my signature z 5 in the presence oftard-.witnesses v RAOUL PIERRE PICTET. Witnesses:

ERNEST H. DE VINE,

D HOWARD HAYWooD.

